A sports statistic is trustworthy in a narrow way: it may accurately describe a defined sample. It becomes untrustworthy when it is asked to describe a different roster, a different era, or a future price. The checklist is a way to keep the first job and decline the others. It fits on a card. It does not require a model.

Say the count out loud

Every rate has a count underneath it. Five games, forty at-bats, a single series. If the person quoting the rate cannot produce the count, the rate is a rumor. Why small samples mislead is what you are checking for. A large count does not make a number wise. It makes the number less twitchy. Write the count next to the rate every time, including when the rate is flattering to your team.

Name what is being divided

Hits per at-bat are not times on base. Points per game are not points per possession. A raw rebound total grows when a team plays faster, which is not the same as rebounding a larger share of chances. If you cannot name the denominator, you cannot compare two players who have different opportunities. Batting average is the worked example of a denominator people silently expand.

Ask whether the figure is a stock or a flow. A season total is a stock that rewards durability and pace. A rate tries to remove those. Mixing a stock with a rate in one sentence is how a compiler of minutes gets called the best at a skill.

Attach the world that produced it

Roster, park, rest, opponent, rules, era. Last week's number may not travel when the roster changes. Home and away splits fail when the park is ignored. A checklist item you skip is the item the story was depending on. If the story collapses once the park is named, the story was about the park.

You will not always have every attachment. Say which ones you lack. A number with a labeled gap is more honest than a number with a confident tone.

Do not give the number a second job

Description is the first job. Cause is a second job. Two figures that move together still need a mechanism, and a third factor such as pace or minutes often produces both. Point differential versus the win-loss record is a pair of summaries people keep merging into one lever. Keep them as descriptions.

A price is a third job. This checklist does not output a wager, a tip, or a side. Where betting is illegal, or where the reader is under the local age, the third job is simply unavailable. Where it is legal for adults, it is still not what a descriptive statistic is for. Close the card after the description. If you wanted a feeling of certainty, the card worked by withholding it.

Frequently asked questions

What is the minimum I should check?

The count, the denominator, and one sentence about who played and where. If any of the three is missing, do not repeat the number as a conclusion.

Are official league stats exempt?

No. Official means the arithmetic was recorded. It does not mean the sample is large or the roster is unchanged.

Can this checklist tell me who will win?

No. It tells you whether a quoted number deserves trust as a description. Prediction and wagering are different jobs, and this list does not do them.

Steps

State the count: Write the number of games, at-bats, or possessions. If you cannot, you do not yet have a rate.
Name the denominator: Say whether the figure is per game, per at-bat, per possession, or a raw total that grows with playing time.
Attach the roster and the setting: Note injuries, park, opponent, and era. A number without those is from a different measurement.
Refuse a second job: Do not turn the statistic into a cause or a wager. Let it stay a description.